There are quite a number of such add-ons, some examples (or search on AMO):

Bookmarks Tab displays bookmarks on new tabs
SessionPage shows opened tabs from last session in a single page
Fast Dial is another way to quickly navigate bookmarks (very popular)
AiOS is an alternative method, using the Sidebar for various tasks

Please let us know how above works out, and if we can be of further assistance. Detailed feedback is appreciated and helps us to help you better, plus enables us to better help other users with similar issues.

There are quite a number of such add-ons, some examples (or search on AMO):
[https://addons.mozilla.org/en-US/firefox/addon/7161/ Bookmarks Tab] displays bookmarks on new tabs
[https://addons.mozilla.org/en-US/firefox/addon/4239/ SessionPage] shows opened tabs from last session in a single page
[https://addons.mozilla.org/en-US/firefox/addon/5721/ Fast Dial] is another way to quickly navigate bookmarks (very popular)
[https://addons.mozilla.org/en-US/firefox/addon/1027/ AiOS] is an alternative method, using the Sidebar for various tasks
... I could go on, but search yourself: https://addons.mozilla.org/en-US/firefox/
Please let us know how above works out, and if we can be of further assistance. Detailed feedback is appreciated and helps us to help you better, plus enables us to better help other users with similar issues.

New Tab JumpStart
When you open a new tab get immediate access to your most frequently used sites, bookmarks, closed tabs, history search. Similar to Google's Chrome new tab feature.

New Tab King
Needs something better than an empty tab? New Tab King creates a personalized launchpad to the sites you use the most, recently closed tabs, suggested sites and more

Ok, I missed the 'most visited' part! :o)
A couple of suggestions from a search on AMO:
[https://addons.mozilla.org/en-US/firefox/addon/8914/ New Tab JumpStart]
When you open a new tab get immediate access to your most frequently used sites, bookmarks, closed tabs, history search. Similar to Google's Chrome new tab feature.
[https://addons.mozilla.org/en-US/firefox/addon/10828/ New Tab King]
Needs something better than an empty tab? New Tab King creates a personalized launchpad to the sites you use the most, recently closed tabs, suggested sites and more